<script setup>
  // 声明周期钩子

  // 与vue2的变化
  // 1. 取消初始化, beforeCreate和created都用setup函数/setup-script代替
  // 2. 更新函数和挂载函数名字前加on
  // - beforeUpdate-- > onBeforeUpdate
  // - updated --> beforeUpdated
  // - beforeMount --> onBeforeMount
  // - mounted --> onMounted
  // 3. 卸载函数更名为unMounted并且加on
  // beforeDestroy --- >onBeforeUnMounted
  // destroyed --- > onUnMounted 
</script>
<template>
  <div>
    <h1>你好</h1>
  </div>
</template>

